Better than colliding and bodies falling from the sky though.
Human Factors and Performance are the limiting factors in aviation. "What is that over there, is it a plane or a window reflecting the sun 20 miles away? I can't quite make out which way it is going, oh shi............." 300 mph closing speed is 5 miles per minute. Maybe easy to see another aeroplane at 1 mile, but this is 12 seconds before impact at those speeds.
Easy to criticise someone else in hindsight sat in front a computer screen.
I've had several "traffic alerts" in my time, one was hidden behind the wing of our Cessna, the other was climing underneath us in a Cessna and we were descending into an airport in a low wing. How is one meant to see those without xray vision?